It is well known that windshield wipers can become stuck, or frozen, to a vehicle windshield in certain inclement weather. Vehicle operators who park their vehicles outdoors at night or during the day often find their vehicle covered in snow and/or ice. In these situations, clearing the windshield of the snow and/or ice is not always sufficient to unstick the windshield wipers from the windshield. Typically, the vehicle operator will have to physically move the windshield wiper to overcome the retentive force created by the snow and/or ice. In addition to being a nuisance for the vehicle operator, physically moving the windshield wiper can also result in damage to the windshield wipers or wiper blades.
In other scenarios, the vehicle owner may start the vehicle allowing it time to warm up and at least partially clear the windshield. This may be done utilizing a remote vehicle start function or manually. In such scenarios, the vehicle operator typically turns on a rear window heater and a defroster to warm the front windshield. Typically, however, the vent through which the warm air blows onto the front windshield in the defrost mode contacts the window above a zone of the windshield where the windshield wipers typically reside when not in use. In other words, the defroster only warms a portion of the windshield excluding a windshield wiper park zone. Again, the windshield may be substantially cleared of snow and/or ice by the defroster but the windshield wiper may remain frozen to the windshield within the windshield wiper park zone,
Although mechanisms have been developed to warm the windshield wiper park zone, these mechanisms are limited primarily to a pre-warming sequence or a sequence which remains on throughout the entire time the vehicle is running. In other words, warming of the windshield wiper park zone whether for a pre-warming period or the entire time the vehicle is running is only initiated by the vehicle owner starting the vehicle, whether manually or remotely, to allow the vehicle time to warm up and at least partially clear the windshield.
While these mechanisms have proven useful in these scenarios to warm the windshield wiper park zone sufficient to release the windshield wipers from the windshield they each suffer from certain drawbacks. The pre-warming sequence, for example, does not account for scenarios where the windshield wiper park zone refreezes after the pre-warming period elapses and the windshield wipers become stuck during operation of the vehicle. In such a scenario, the vehicle operator has to cease operating the vehicle to address the issue manually, continue operating the vehicle without windshield wiper function, restart the car in order to re-engage the pre-warming sequence, or engage a human machine interface (HMI) to initiate a new warming sequence if the particular vehicle has an HMI. The warming sequence which occurs throughout the entire period of time the vehicle is operating likewise has drawbacks. Primarily, the continuous warming sequence consumes a significant amount of current throughout the sequence. Some, or even most, of this current consumption could be occurring during periods where warming is no longer required due to ambient temperature increases and/or a lack of need for windshield wiper function.
Accordingly, a need exists for a way to prevent a windshield wiper from freezing to a windshield park zone that is not limited to a pre-warming sequence, a continuous sequence, or manually engaged sequences utilizing HMI. Ideally, the warming sequence would be initiated when the ambient temperature is near or below freezing and when the vehicle operator indicates a windshield wiper function is needed. In order to avoid starting and stopping of the sequence for intermittent use of the windshield wiper function, the warming sequence could be initiated after the windshield wiper function had been engaged for a period of time. The warming function could also extend until the windshield wiper function is disengaged or until the ambient temperature is sufficient to avoid freezing.
Even more, the warming sequence could be combined with the pre-warming sequence to ensure proper windshield wiper function at start up and throughout operation of the vehicle while limiting current consumption and eliminating the need for the vehicle operator to engage HMI. The warming sequence could also be combined with other vehicle functions that might indicate a need for warming the windshield wiper park zone.